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root, in mathematics

(Encyclopedia)root, in mathematics, number or quantity r for which an equation f(r)=0 holds true, where f is some function. If f is a polynomial, r is called a root of f; for example, r=3 and r=−4 are roots of th...

beta-blocker

(Encyclopedia)beta-blocker or beta-adrenergic blocking agent bāˈtə ădˌrənûrˈjĭk [key], drug that reduces the symptoms connected with hypertension, cardiac arrhythmias, angina pectoris, migraine headaches, ...

ventricular assist device

(Encyclopedia)ventricular assist device: see under heart, artificial. ...

eclecticism, in art

(Encyclopedia)eclecticism ĭklĕkˈtĭsĭzˌəm [key], art style in which features are borrowed from various styles. It was once applied to the Carracci, who incorporated elements from the Renaissance and classical...

transcendentalism , in philosophy

(Encyclopedia)transcendentalism, in philosophy, term descriptive of systems that hold that there are modes of being and principles of existence beyond the reach of mundane experience and manipulation. The term is n...

Richards, Dickinson Woodruff, Jr.

(Encyclopedia)Richards, Dickinson Woodruff, Jr., 1895–1973, American physician and physiologist, b. Orange, N.J., grad. Yale, 1917, M.D. Columbia, 1923. He joined the staff of the College of Physicians and Surgeo...

time , in music

(Encyclopedia)time, in music: see tempo; meter; rhythm; syncopation; metronome and musical notation. ...

periwinkle, in zoology

(Encyclopedia)periwinkle, any of a group of marine gastropod mollusks having conical, spiral shells. Periwinkles feed on algae and seaweed. They are found at the water's edge; out of water, they resist drying by cl...

ray, in physics

(Encyclopedia)ray, in physics, term denoting the straight line along which light or other form of radiation is propagated from its source. It generally refers to the line of propagation of waves but is also applied...

calcium-channel blocker

(Encyclopedia)calcium-channel blocker, any of a class of drugs used in treating hypertension, angina pectoris, and certain arrhythmias. They prevent the calcium ions needed for muscle contraction from entering the ...